Short answers, pulled from the story.
Socialism is an economic and political philosophy characterised by social ownership of the means of production, as opposed to private ownership. Social ownership can take public, community, collective, cooperative, or employee forms, and socialism is the standard left-wing ideology in most countries.
Pierre Leroux claimed he first used the term socialism in the Parisian journal Le Globe in 1832. Leroux was a follower of Henri de Saint-Simon, one of the founders of what later became known as utopian socialism. The word's root is the Latin sociare, meaning to combine or to share.
An early distinction held that socialism aimed only to socialise production while communism aimed to socialise both production and consumption through free access to final goods. The idea that socialism and communism are distinct historical stages entered the Marxist lexicon only after Marx's death, and was sharpened when Lenin defined socialism as a stage between capitalism and communism.
Democratic socialists seek to replace capitalism with a socialist economic system, while social democrats support a welfare state, unemployment insurance, and progressive reforms of capitalism that aim to administer and humanise it. Social democracy embraced a mixed economy based on Keynesianism within a capitalist market economy in the post-war period.
The major socialist movements include anarchism, communism, the labour movement, Marxism, social democracy, and syndicalism. Other variants include African socialism, Arab socialism, ethical and liberal socialism, libertarian socialism, religious socialism, and eco-socialism, each differing on the role of markets, planning, and the state.
Socialism experienced a resurgence in popularity in the 2010s due to the 2008 global financial crisis. Figures such as Bhaskar Sunkara, founding editor of the magazine Jacobin, argued its appeal persists because of inequality, the exploitation of wage labor, and ecological crises such as climate change.